Because technical criticism isn't the be all and end all, as much as people would like to believe. You should always question people and companies motives, you seem to be happy to question my motives, but can't apply that to Mir/Canonical?
If they aren't hiding something, and we can believe they believe they have the technical competence to design a replacement for wayland/X then you'd expect them to have the technical competence to understand wayland/X? Its generally considered a good idea to understand the thing you are trying to displace. Now if you write a page of falsehoods on the things you are trying to displace, you are either acting from malice, deliberately lying, or stupidity, lying through lack of knowledge. As I said on my blog posting, neither of these reasonings are the things I want to see from the group designing the next generation of display server.
What part of, I do not speak for Red Hat, makes no sense to you. Just because someone gives me a pay cheque it doesn't translate me into a mouthpiece for them. I know its probably hard to understand for people who've never worked in an environment like Red Hat. I have a position in the Linux community and I make statements that I feel like making, if something pisses me off, I say this pisses me off, and try to analyse why! so what if I don't like Canonical, their methods of open source development are anti-community and the direct opposite of how every open source project I've worked on has worked. So maybe I make petty one liner statements, shoot me, its the Internet.